local cmp = require("cmp")
local luasnip = require("luasnip")

local has_words_before = function()
  local line, col = unpack(vim.api.nvim_win_get_cursor(0))
  return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

cmp.setup({
	snippet = {
		expand = function(args)
			require("luasnip").lsp_expand(args.body)
		end,
	},
	mapping = cmp.mapping.preset.insert({
    ["<Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_next_item()
      elseif luasnip.expand_or_jumpable() then
        luasnip.expand_or_jump()
      elseif has_words_before() then
        cmp.complete()
      else
        fallback()
      end
    end, { "i", "s" }),
    ["<S-Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_prev_item()
      elseif luasnip.jumpable(-1) then
        luasnip.jump(-1)
      else
        fallback()
      end
    end, { "i", "s" }),
		["<C-Space>"] = cmp.mapping.complete(),
		["<CR>"] = cmp.mapping.confirm({ select = true }),
	}),
	sources = cmp.config.sources({
		{ name = "nvim_lsp" },
		{ name = "luasnip" }, -- For luasnip users.
		{ name = "buffer" },
	}),
})

-- Set configuration for specific filetype.
cmp.setup.filetype("gitcommit", {
	sources = cmp.config.sources({
		{ name = "git" }, -- You can specify the `git` source if [you were installed it](https://github.com/petertriho/cmp-git).
	}, {
		{ name = "buffer" },
	}),
})

-- Use buffer source for `/` and `?` (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline({ "/", "?" }, {
	mapping = cmp.mapping.preset.cmdline(),
	sources = {
		{ name = "buffer" },
	},
})

-- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline(":", {
	mapping = cmp.mapping.preset.cmdline(),
	sources = cmp.config.sources({
		{ name = "path" },
	}, {
		{ name = "cmdline" },
	}),
})
